Zenas BioPharma, Inc. completed a public offering of $200,000,000 aggregate principal amount of 2.50% Convertible Senior Notes due 2032 (the Notes) on March 31, 2026. The Notes will accrue interest semiannually at 2.50% per year, starting October 1, 2026, and will mature on April 1, 2032. Noteholders can convert their Notes into cash, common stock, or a combination, under specific conditions, including if the common stock price exceeds 130% of the conversion price or if the Notes' trading price falls below 98% of the stock price multiplied by the conversion rate. The initial conversion rate for the Notes is 37.7358 shares of common stock per $1,000 principal amount, equating to an initial conversion price of approximately $26.50 per share. The Company has the option to redeem the Notes on or after April 8, 2030, if certain stock price conditions are met, at a cash redemption price equal to the principal amount plus accrued interest. Noteholders can require the Company to repurchase their Notes upon a Fundamental Change (e.g., certain business combinations or delisting events) at the principal amount plus accrued interest. Concurrently, the Company completed an equity offering, selling 5,000,000 shares of its common stock at $20.00 per share. The underwriters for both offerings were granted options to purchase additional Notes ($30,000,000 principal amount) and shares (750,000 shares) to cover over-allotments. The net proceeds from the Convertible Notes Offering were approximately $193.7 million, and from the Equity Offering were approximately $93.7 million, totaling approximately $287.4 million. Proceeds are intended to support the planned U.S. commercial launch of obexelimab for IgG4-RD (if approved), advance the development pipeline (orelabrutinib Phase 3 for progressive multiple sclerosis, ZB021 Phase 1 and Phase 2 clinical development), and for working capital and general corporate purposes.